1. Technical Field
The present invention generally relates to a gas valve, and more particularly to a plug member of gas valve.
2. Description of Related Art
It's well known that a plug member installed in a gas valve is adapted to regulate the gas flow passing therethrough. Taiwan utility model patent M276159 discloses such a conventional plug member which is adapted to be installed in a main body of a gas valve, including a gas channel provided therein, wherein a first vent and a second vent communicating with the gas channel are provided on an outer wall of the plug member. A variable area slot is further provided on the outer wall of the plug member. The disclosed plug member is adapted to regulate gas flow passed through the gas valve in a nearly linear way, for the cross area of the variable area slot is specifically designed, wherein the first vent allows high gas flow to flow into the gas channel, the second vent allows low gas flow to flow into the gas channel, and the gas supply does not cut off while rotating the plug member between the first vent and the second vent.
As shown in FIG. 1, in practice, lubricant is applied to an outer peripheral surface 10a of the plug member 10 to increase the lubrication between the plug member 10 and the main body of the gas valve. However, for the conventional plug member 10, a top margin of the variable area slot 104 near the second vent 102 is perpendicular to the rotating direction of the plug member 10, making lubricant accumulate in the variable area slot 104 at locations near the second vent 102. Once lubricant accumulates too much, the gas channel would be blocked, which would cause the gas flow to drop dramatically or even to be cut off completely while rotating the plug member 10.